Centimeter wave velocity modulated electron discharge device



4July 15, 1952 E. Ros'rAs CENTIMETER WAVE VELOCITY MODULATED ELECTRONDISCHARGE DEVICE Filed may 2'1, 1947 2 SHEETS-SHEET 1 IIIIV FIG.

Illvm FIG, 4

| Ul I I I I *i FIG. 3

FIG.

FIG.

IN VEN TOR.

ERN EST R OSTAS A TTOPNEV FIG. I

`)uly 15, 1952 E. Ros'rAs 2,603,764

CENTIMEITER WAVE VELOCITY MODULATED ELECTRON DISCHARGE DEVICE Filed May21, 1947 2 SHEETS- Smm 2 s llilllllllj 7| 7069 84 7 lll-NA IN VEN TOR.ERNEST ROSTAS.

A TTORNEV 7 FIG. 9

Patented July 15, 1952 CENTIMETER WAVE VELOCITY MODULATED ELECTRONDISCHARGE DEVICE i' Ernest Rostas', Paris, France, assignorv toIntervnational Standard Electric Corporation, New York, N. Y.,`acorporation of Delaware I Application May 21, 1947, serial No. '149,511In France June 15, 1939 -ASectionvL Public Law 690, August 3, 1946Patent expires `lune 15, 1959 The present invention relates to means forthe control of electronic discharges and devices making use of suchmeans.

These means and devices are particularly applicable vto high frequenciescorresponding to wavelengths of the nature of a meter and a centimeterdown to a'few millimeters.

' The invention has in particular for one of its objects the provisionof means whereby the electrons oigan electronic discharge may be sep-.aratedsubstantiallyinto two groups of distinct mean transversalvelocities in accordance'with a desired law of control. Y

' Another object of the' invention is 'the provision of means wherebyone of these groups vof :electrons of differing mean transversalvelocities `may be vused as desired with a view to extracting Aenergyfrom the selected group in an..out going circuit.

The term transversal velocity of the electrons is understood to mean theperpendicular velocity component in the magnetic field used;

lOther objects of the invention further rest in the design of thestructure of the electronic discharge devices making use of a controlledseparation of the electrons of a discharger as also the ymeansV for the.production of an .electronic discharge whose structure Awould beparticularly favourable in order that this separationfmight be realised.'l f.. In 'accordance with certain of its characteristics, the inventionprovides for controlled means of separation of electrons in accordancewith .their transversal'velocities,comprising a magnetic field directedalong the 'general axis yof the electronic discharge beam and a highfrequency electric field with a direction which is substantiallyperpendicular to the axis of the 'said beam.

In accordance with another characteristic. of the invention, theelectronic beam used does not 'consist substantially lof electrons whosedirection of ldisplacement, is along the axis'of the beam.'.

In accordance with another characteristic of iifclaims. (C1. sis-:6r

theLinvention, means are. provided to eliminate l `according to theirabsolute tangential velocity by means of, for example, reflectionelectrodes.

InA accordance with other characteristics of the invention, theelectronic discharge devices comprise two or more distinct regionswhich'are traversed in succession by a single beam of electrons, a magneticfield being directed in accordance with kthe axis of rthis beam and anelectric high frequency eld traversing each of the said regionsfollowing a direction vwhich islsubstantially perpendicular to the axisof the said beam.

In accordance with other characteristics 'of the invention, theelectronic discharge devices comprise. two or more distinct regionstraversed in succession by a single beam of electrons not includingelectrons which shift alongv the axis of the beam at the entry to thefirst region, a magnetic field being provided parallel to the axis fofthe said beam and the high frequency electric elds substantiallyperpendicular tothe axis of the said beam individually associated withthev said regions.

In accordance with other characteristics of the invention, theelectronic discharge devices comprise a first region in which anelectron beam penetrates which does .not have any electrons whose.direction of shift is strictly parallel to the axis of the said beamfor the input of the said volume, a magnetic field directed along theaxis of the beam and ahigh frequency electric eldsubstantiallyperpendicular to the axis of the said-'beam traversing this region,means for selection Vat the output of the said region of'one of the'twogroups of electrons which are'forme'd there, and a second regiontraversed by selected electrons, a high frequency electric fieldV beingprovided in this region transversally with relation to the axis of theelectron beam'selected and a magnetic field following the axis-of thebeam which may be the same magnetic -eld as that whichtraverses'theiirst region.v

In accordance with other characteristics of the invention, theelectronic discharge'devices comprise means for the generation of a'conic beam of` electrons without axial electrons,A this beamconverging'substantially towards the inputof a region in which amagnetic field isA provided in the axis of the beam and a high frequencyelectric field substantially perpendicular to this axis, means at theoutput of this region for the elimination of electrons fromone of thetwo groups being produced whilst theregion is traversed, a second regionequally provided with a high frequency electric eld which is transversalAto the axisof the electron beam which is not eliminated, and alsocrossed by an axial magnetic eld which can be the same as that whichcrosses vthe iirst region, and means for the collection of the electronsat the output of the said second region.

in' which the devices lareus'ed'; Y

In accordance with yet other characteristics of the invention,electronic discharge devices in- Y 4clude means forAv generating a beam`of electrons,

means modifying. the transversal velocities of the electronsof thebeam'with a View toproducing two groups of differing mean transversalveof a beam into two groups of electrons of varying l transversalvelocities Will be explained with referlocities, means for theelimination of one of thesel I' groups of electrons, and for vthe useand collection of the electrons of the remaining group; In accordancewith anothencl'iaracteristic of the invention, means for thegenerationofa confie` cal beam Where thereis a converging of electrons substantiallyfocussed on the input of the rst ence to Figs. l, 2 and 3. This systemcomprises a 'pair of `parallel conducting plates l and 2 bei tween whicha beam of electrons 3 is transmitted.

i force are indicated at E and provided with arrows A high frequencyelectric field whose lines of Y vindicating the instantaneous directionof the eld modifying unit of the transversall velocities of theelectrons, consist in an emissive electrode and an electronicconcentration lens.

In accordance with another characteristic 'of the invention, means forthe eliminationof one of thef'groups of electrons according v:to theirtransversal speed consist in a diaphragm collect -ing all the electronswhose transversal speeds are vgreater .than acertainivalue..

' In accordancewith'another characteristic-.of

'the invention, means vforthe elimination .of one -ofthe-groups'ofelectrons according to their transversal velocities consistin aireecting electrode .which only permits the-free transmission toelectrons of transversal velocities greater than ,a certain.velocity andreiiecting the electrons of lower velocities in their `'direction Vofarrival, orlif desired, in a different direction.

In accordance with yet other characteristics; of the invention,l severalbeams of electrons lnothav- A-ing axial electronsjvhen they varegenerated arev sent parallel in the same direction, or in oppositedirections across regions such asthe above-'inem tioned. I

According to yet other characteristics-the invention provides devices4such. as those Aabove. de-

scribed, fparticularly'adapted to be associated asoscillatorsfrepeaters,detectors'etc. in systems for thetransmission ofWaves'iby dielectric guides.`

:The invention will be explained in detail in the following'descriptioni based onl the attachedK drawingsinwhichi f Figs. l and 2diagrammatic'ally represent in longitudinal andr transversesectionsrespectively a devicej modifying the` transversal velocities of 'theelectrons inY such awayv as `:to obtain *two groups of! electrons ofdiiferingfvelocities, Fig. 3 indicating the examples offthe `paths of--trons at .the output of this device; 'j Fig. 1 4-vshowspdiagrammatically an example` 'of the discharge deviceincorporatingv certain characteristics of'theinven'tion with; means-forthe the siecelimination ,of theelectronsof greater transversalvelocities;yandfof 'using the electrons...with low velocities; f f Y','Fig. 5 Ashows,diagrarnmatically in transverse vsection thepaths'-oflthejelectrons in the system according to,v the Yinvention.,Figzl 6`shows-diagrammatically an example of Y vthe dischargedeviceincorporating certain characteristics of the invention with meansfora the Aeliininaticnzfof theelectrons of lesser :transversalA'velocities and'of using the electrons ofhigh transversalrvelocities; y4 Y Y y,

,Fig. 7 showsl diagrammatically an example of the'v structure-forthe'generation ofa-v beam of electrons, particularly suitable forusein the devices of the present invention; Vand l Figs. 8, 9 and l0show in lateral view, in part in section, in elevation in section, andin detailed view an example of an embodiment ofthe device is appliedbetween these plates. The. electrons move, 'as shown, following ahelicoidal path which will be inscribed on a cylinder of a conv stantradius if they are only subjected to a magvrinstant may have atransversal velocityfwhich is such that it is ready to follow one ofthecircular paths 5, 6, Vl or 8. -If the electronxhad a velocity which wassuch;that itfollowed the path 5 of the'electric iield, itwouldberetarded at a considered moment'where the electric 4field Was inthe instantaneous direction represented by the arrows of the lines. offorce. E, and it would describe inthis case a path offa smallenradius.When it traverses at 18,0,of itspath; it `would again be retarded,sincetheelectric :fields-.Would not rthen be inversed, and so on 'inthe periods following. In this way. such VanI electron kwould follow inits passage between the plates l 'and 42 a path suchas shownat 9 in Fig.3. If, onthe other hand, the electron had a transversal velocity suchthat it followedunderthe action ofthe magnetic field only, thepath6,`itfwould be accelerated `by the electric vield periodically with eachso that it Ywould ,describe a total. path during its passage `betweenthe plates il and2 such assh'own in Hl on Fig'. 3. If itisito follow oneof the paths I and 8, it'will be alternately accelerated and retardedWitheach 180 or vice versa, lso that' its transversal velocity willnotlin practice be affected Von an average bythe existence of theelectric field. i

The operation of the system of invention, will therefore, resultin theproduction of two relatively distinct electron beams, one of acceleratedlOnthis figure simultaneouspaths I6, I1 and I8 of electrons I9; 2! and2i have been shown. These paths are circles andthe electrons have allbeen indicated in the same positions with relation'to these paths-thatis to say, above their paths in the case shown. These electrons all turnin the direction indicated by arrows 22' and will be sub,- ject tolalternative transversal shifts such as `indif cated by the doublearrows 2.3, these alternating shifts'being co-phased and in consequencethe entire cloud of electrons 'will oscillate between plates Iland I5,thus losing the energy which will be collected by the said plate intheform of oscillatory energy which will be used in' a.

circuit not shown, connected to these plates. Their'paths will inconsequence be more and more narrowed as shown at 24 in Figs. 4 and 6and will be finally received by an'electrode or System of electrodesprovided for this purpose and dia'grammatically shown at 25 on these twogures. This'electrode 25 may be brought to a potential which is suchthat the electrons are retarded and received at a very reduced velocitywith a view to decreasing the power consumption of the device.

The devices in the twoAk Figures 4 and 6 only differ, moreover, by thegroup of electrons selected forutilisation. The modification systems ofthe transversal velocities ofthe electrons and 4 between the two pairsof parallell plates I--2 and I4-I5, the potential of this cylinder beingnegative with relation to the pair of plates I 2. The reflectedelectrons may return-in the opposite direction in their direction ofarrival, as shown at 28 in Fig. 6, or the reflection electrode may bearranged at a certain angle to the general direction of the electronicbeam leaving plates l.-2 so asto send the reected electrons outside thespace between the plates. f

In the devices in accordance with the invention, equally the magneticeld should be provided along the entire length of the structure and notsimply between the plates I and y2.

AIt should be noted that in the case where the reflected electrons aretransmitted between plates I and 2 they create in some degree areactance or return feed of electrons. Such a reactance may be providedif desired by transmitting a beam of electrons between the plates I4 andI5 Vso that the two plate systems serve simultaneously for inputstructures and for use yat the device. f

The means for generating the beam have not been considered up to thepresent. If the'beam ,of electrons transmitted between the plates I and2 is in its origin a parallel beam, all the electrons willbe subjectedto a transverse acceleration at the expense of the'energybf the highfrequency eld. It is, consequently, necessaryto use a conical electronbeam which has no .elec- Atrons which move. axially when they enter' thepole-piece of theelectromagnet or magnet creatv ing `the magnetic fieldH. This electroae',lortl'iis pole-piece, concentrates the electronsemittedby the electrode 29 into `a hollowc'onical beam 3| whichconverges approximately on tothe input of the plates I-2. Between ftheplatesl and 2 this beam takes the' form indicated at'3 on the Fig.l. f

On this Fig. 7 by way of illustration the electric connections of theelectrodes 28, 30 and I'-2 have been shown with relation to a source S.

l vThe devices of the present invention maybe arranged to operate eitheras oscillatorsor` as detectors, demodulators, repeaters, Ufrequencychangers etc. They maybe incorporated in ultra short-wave transmissionsystems, for example, they may with advantage be applied in systems forthe transmission of waves by dielectric guides. An embodiment of thedevice ci this kind whose structure is' arranged for adaptation in a4transmission system with dielectric guides is vshown in Figs. 8, 9 andl0.

In these gures an external sheath which is of metal in the examplechosen, butwhich may equally be of insulating material, is of such aform that it has four open extremities, two'by two opposite to oneanother, 5I--52 and 513-154'. These extremities are of a suitable vformand dimensions to be adapted to the ends 'cfdielectric guides, shownhere for greater simplicity in the form of a cylinder with a circularsection', although they may have any desired straight section usual inthe art of dielectric guides, that is to say, they may be elipsoidal,oval,square, rectangular, polygonal etc. The connections between theextremities 5I-54 of the external sheath 5f) and the sections of theguide, of vwhich two only are shown cn the right-hand side of thedesign, thus and 5B are constructed So -as to be airtight, for example,as shown by means of ,the insulating junction tubes 5'! and 58 sealed atthe two extremities on the metallic extremities adjacent to the sheath,and the guide sections, Aand provided withv dielectric transversalairtight cellular constructions such as 59. These Y cellularconstructions may either be of one piece '.ample, by pulverisation orprojection, or any other suitable manner, and which is shown at on thedesign on each side of the transversal cellular constructions. I I

Two metallic tubes 6I and 62 open lat either lend are arranged insidethe sheath between` the extremities 5I-52 and v53-54v respectively,andare heldin place by the insertion of their extremities inside enclosedportions 5Il54 of the external sheath. These ends may be split as shownat 63 to permit of freer expansion or contraction under the influence oftemperature fluctuations. Thesemetallic tubes 6I and 62 are pierced withapertures 64--65 and 66-61 which chanically'and electrically.

lar constructions,

acca-,764

diaphragmzmaypreferably be also electrically an integral part Yof V thenlament 69. Thesev-.electrodesia'recarried by the cylinderV 6l throughthe mediuln'of the insulating rings '12 and 'I3 on which the conductorrings 14 andr 'I5 are threadedi to Ywhich'latterithe electrodes arefitted me- The cylinder 68 is carried by its own electric connection 16,Fig. 9.

Onthe side of the external opening 61 to the cylinder 62 a collectorelectrode 'l1 is placed for the. electronic beam which transversesinsuccession the volume 6|V through the openings 64 and 65; the conductorvcylinder-68 and the volume 52. across the openings 66 and 61. Thiscollector electrodev 'Vl' is preferably supported by its electricconnectionA 'i8 which crosses the sheath 50 in such a way as to beelectrically insulated;

f Asmay be seen on Fig. 9, the electric screen 10, theA lament 69 andthe diaphragm -ll are mechanically spaced by insulating cross-pieces 19.

A magnetic field parallel to the general direction of the electronicbeam emitted by the filament is obtained by means, for example, of an`el'ectrornagnet Whose pole-pieces are indicated at 80 and 8 I. v Adevice of this kind operating inthe manner explained with regard to Fig.6 may in particular be used in a system for the transmission of wavesbydielectric guides. For this purpose a section of the'incoming guide isassumed to be connected to the end I of the device and a section of theoutgoing guideis shown at 56. In these guide sections the waves arrivein the device by the en'dllfv4 as shown by the arrow 82 and leaveyby theextremity 56 as shown by the arrow 83. Conductor pistons 84 and 85reflecting the waves are provided in the other guide sections with aView to ,adjusting the agreement of the volumes by the sliding motion ofthe pistons. 'I'hese pistons arelprefe'rably in the portions'of thedevice in which Vthe vacuum is notV made, but which are ,.lled bya'gaseous dielectric; for exam-ple, with air. "The vacuum is onlyensured inside the sheath up to the transversal dielectric cellutheconducting continuity beingrealised as nearly as possible between thecylinders 6| and 62 and the sections of the dielectric guide byconducting coatings 6D. y

Y In order to use the oscillator device a reflecting piston isfalsoprovided in the guide connected to the end 5| and the return coupling ofthe energy of the high frequency Waves necessary for the V,creationandmaintenance of the oscillations is ensured, for example, by aconnection with lecher r wires'e terminated by two loops 81 and 88 or inany other suitable manner, for example, by a dielectric guide section. Y

Another means of return coupling may consist in accordance with anothercharacteristic of the Ainventionin a beam of electrons crossing the vtwo spaces 62 and Bl in the opposite direction of with relation to thebeam and to the volumes,V as

shown schematically at 89. y

f In order. to use thedevice shown asy an amplia ier on the other handthe return feed circuit 86 may; or may not be-suppressed, and theincomingwaves are transmitted-.in the direction sho-wn by the arrow-82,- and go outas shown by the arrow.- Y l A device of this-kind mayalso' be usedesja detector, or demodulator by transmitting the modulatedcarrier wavesV in the device Yin 4thedirection of 'the arrow 82, and bycollecting jthe demodulated or detected Vwaves on the electrode Tl. Thepotentials of the electrodes are adjusted in such a manner as toensuredetection; for example, the electrode r'I7 may be connectedv tothecathode :through a resistance making use of the demodulation'products, f

In order to use the tube as a modulator Vthe diaphragm 'H isdisconnected from the filament and/fed by a modulating potential which,corr-- sequently, modulates the intensity of the-cathode beam-.emittedby the filament.

A `feed circuit of ythe electrodes of thel device described has beenshown by way of example in the case oi operation as an amplier. Thereilector cylinder 63' isy connected to a Vnegative point of theYbatteriy'lik of which another point-y less negative,v is connected tothe filament. 'I'he positiveYV end of the'battery Si! is connected in*parallel tothe two cylinders El and 62Y and a Ypositive intermediarypoint of the battery i's connected to the collector electrode ''Ifwith aview to retarding the electrons in the utilisation'cylinder B2' and tocollecting them lwith a very re'- duced velocity which diminishes thelosses in energy of theA structure. VA Yiilament heating battery 9l` isshown' connected to a point'of the screen 'mand al pointof the filament69. YA11 the Vfeed leads of` the generator and collecting electrodes ofthe beam are insulatedin the external sheath as also'the cylinderl whenthe potential of the cylinders 6l and 52 is directly applied to thesheath 50 vvsince this latter is assumed to be metallic in the caseshown.Y The guide section' 56 may obviously terminate if` desired by awave radiator system inspace, or in Waves, or in incoming Waves whichmay originate in a collector system of waves radiated in space. Y

Althoughv the inventionV has been described With regard to vcertainparticulerembodimentsit is clear that itisv not in the least limited tothese, but is on the contrary capable jofjnfumerous modifflcations andadai'atations;y withoutvleaving. its

domain. i i

Ircl'aim: f "fp j 1. An electron discharge device includingY a source ofelectrons for projecting a'stream ,y of Y electrons in a path, meansabout said path adjacent said 'source forV generating an alternatingkelectric eld substantially transverse to the flow of electrons fromsaid source, means about said tpathiorV producing a magnetic fieldextending generally longitudinally of said flow Vof electrons from saidsource, a first electrostatic means about said path adjacent saidalternating eld generating means for preventing the passa-ge of some ofthe electrons in said now, and a second electrostatic means about saidpath adjacent said first electrostatic means for extracting alternatingenergy from the electrons which pass said iirst electrostatic means.

v2. An electron discharge device according' to claim l, in whichsaidmeans for generating an alternating electric eld includes a cavityresonatorresonant at the operating frequency disposed in communicationwith said path between said source and said iirst electrostatic means.

3. An electron discharge device according to claim 2, in which saidsecond electrostatic means includes a cavity resonator resonant at theoperating frequency disposed in communication with said path adjacentsaid first electrostatic means. f

4. An electron discharge devicev according to claim 3, in which couplingmeans are provided for feeding back energy from said electrostaticenergy extraction means to said electric field generating means.

5. An electron discharge device according to claim 4, in which saidcoupling is made by means of lecher Wires coupled between said cavityresonators.

6. An electron discharge device according to claim 1, in which saidelectrostatic means for preventing the passage of some of the electronsin-V cludes a diaphragm frame disposed generally normal to the iiow ofelectrons and' having an aperture generally coaxialwith the iiow ofelectrons and coupled to a source of potential negative with respect tothe potential of said energy extracting means.

7. An electron discharge `device according to claim 1, in which saidelectrostatic means for preventing the passage of some of the electronsincludes a hollow cylindrical member extending generally longitudinallyof and coaxial with the flow of electrons and coupled to a source ofpotential negative with respect to the potential of said energyextracting means.

8. An electron discharge device according to claim 1, in which saidsource of electrons includes means connected thereto for modulating theoutput of electrons from said source in accordance with a modulatingsignal.

9. An electron discharge device according to claim 5, in which saidcavity resonators are portions of input and output hollow conductingwave guides, each having apertures generally concentric with the flow ofelectrons to permit such iiow.

10. An electron discharge device according to claim 9, in whichadjustable means are provided in said cavity resonators for adjustablyvarying the oscillating characteristicsof said resonators.

11. An electron discharge device according to claim 10, in which saidadjustable means includes a plunger or piston adjustably slidable Withinone of said resonators.

12. An electron discharge device comprising a pair of high frequencyelectromagnetic Wave guides disposed in adjacent relation, a housingenclosing corresponding lengths of said guides, said guides havingaligned apertures therethrough, an electron emitter and an electroncollector in said housing disposed in spaced relation on opposite sidesof said guides and in alignment with said apertures to define anelectron beam path transversely of said guides, means to produce amagnetic eld axially of said beam path, an annular electrode disposed insaid housing between said guides and means to bias said annularelectrode at a potential to cause certain claim 12,'further includingmeans to terminate eachof said guides to one side of said apertures. 14.An electron discharge device according to claim 12, further includinglecher wires coupling said guides for return flow of energyvtherebetween.

ERNEST ROSTAS.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS

